Step 1: The Antenna

Here we see a close-up of the antenna. A hole has been drilled into the PCB to accept the N-type chassis connector. Note the sheet of plastic. My initial thought was to shied the plate from the antenna but subsequent experiments have shown no change in signal strength so you do not need this plastic shielding.

You can also see the antenna constructed from the 1mm earth wire. You need to bend the wire so that it forms the diamond pattern as in the photo. Each side of the diamonds are 30.5mm. At the crossovers the wire does not touch itself.

One end of the antenna is soldered to the N-type at a height of 15mm from the collector plate. The other end is attached to one of the bolts holding the N-type chassis connector in place.

Step 2: Rear of Collector Plate

Here we see the rear of the collector plate, with the N-type bolted in place. Here is where we screw on the N-type to SMA adaptor.

Step 3: N-type to SMA adaptor

This is the N-type to SMA adaptor. Most WiFi stick antennas use SMA connectors so you will need to make your bi-quad compatible.

I am in the process of building a single biquad out of a dish 500. I plan to mount the Alfa inside of the dish and USB out it's lower end into the laptop. It stands on a modified tripod guitar stand. It will of course be modified from the instructions (linked)http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/A personality on another forum told me that he has achieved 175 miles with his biquad in ideal conditions. Though I expect that to be an overstatement, I still will be expecting to see most of the APs in my small city of 100k people so it should be pretty noisy..I am also researching converting everything (including my Alfa) over to type F connections for universality. I understand that 50 ohm is the RF standard so I figure 50 OHM connectors and a very short length of 400 series coax cable will do the trick.I will report my findings in a few weeks.Peace

I'd very much like to read your findings so make sure you post a link.

I think all the long distance connections are set up rather than random finds. In other words the claimer is optimising both ends; maybe a high-power AP (possibly with a dish at that end too) and then searching only for that AP.

I can get about 40 APs, in my street alone, with my current setup. The number of open and WEP APs is very small. Time to cast the net wider.

The minimum range I will accept is roughly about 1500 yards, but of course I'd like a few miles of range.

Your suggestion makes perfect sense regarding both ends being dish equipped. I'd bet that the AP had a unidirectional amplified feed as well, and possibly from a higher elevation to a lower on a fair weathered day.

Your approach is very professional and I thank you for your attention to detail. I will be building a parabola by using a giant umbrella and I was hoping to use this as an nlb to it, how small can I get when I build a bi-quad you think? 5cm x 5cm?thanks

Firstly, I am not sure if an umbrella will work as it has no reflective qualities. An old satellite dish would be the thing to use. Unless you can coat the umbrella with foil or something that will reflect microwave radiation.

As far as the bi-quad is concerned, the bigger the better. Also the more elements the better. I have seen much bigger with many more elements.